What an interesting confluence of situations and people!

I just noticed oil in my coolant tank the other day and my car is at this moment getting a new head gasket at....Mr. MB, a recommended indie in Tarzana, CA.

My car, 1991 300CE, about 124,000 miles, M104 engine.

I had been checking the coolant rather closely after a recent repair of a leaking coolant hose (the nasty little one under the intake manifold, connecting the block to the oil filter housing) and immediately noticed the oil stains in the coolant tank.

It is going to be about $1600. You can drive the car but as mentioned, all your coolant hoses will need replacing (tech said about $500 worth of hoses). I caught it pretty early, only a little scum in the tank. Tech said some cars come in with a 1/2" of oil floating in the coolant tank. Tech said it does take repeated flushing to get the oil out of the system.

From what I understand, there are external and internal head gasket failures common to the M104. Most people experience the external leaking oil out the right rear. Less common is the internal leak, typically brought on by an episode of overheating. My car did get very hot in July after a thermostat failure. I pulled over before pegging the needle but that may have been just enough.

Did you have a recent overheating?

glenmore
1991 300CE